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When to Plant Valerian in Henderson County, KY

Henderson County, Kentucky Zone 6b April

Your April gardening checklist

April rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Henderson County, Kentucky.

Avg. last frost April 5
Avg. first frost October 31
Soil temp (4") 43°F
Watering Low
Pest pressure Low
Daylight 13 hrs
  1. Move valerian from tray to bed

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

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Valerian is a tall perennial herb with fragrant white or pink flower clusters, valued for its root which is used as a natural sleep aid. It attracts pollinators and earthworms.

Henderson County, Kentucky is in USDA Zone 6b. The average last spring frost is April 5 and the first fall frost is October 31, giving you a growing season of approximately 209 days.

At an elevation of 3,992 feet, Henderson County receives approximately 47.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Valerian during the growing season.

Henderson County, KY (Zone 6b) Long season
209 days
Last Spring Frost April 5
209 growing days
First Fall Frost October 31

Henderson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (6 days to spare)
Transplant: Apr 5 🍅 Harvest: Aug 9 – Oct 18
Recommended (50%) ✓ Fits season (6 days to spare)
Transplant: Apr 12 🍅 Harvest: Aug 16 – Oct 25
Safe Start (90%) ✓ Fits season (14 days to spare)
Transplant: Apr 25 🍅 Harvest: Aug 29 – Nov 7

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Henderson County

How your county's soil matches Valerian's growing requirements.

Soil pH

Your soil pH (5.3–7.1) overlaps with Valerian's range (5.5–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Henderson County is excellent for Valerian — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Valerian.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Valerian.

How to Plant Valerian

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Valerian

Valerian needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Valerian Needs Rainfall You Supplement Action
Jan 3.6" 0" ❄️ Dormant
Feb 3.3" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.9" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 3.5" 0" ❄️ Dormant
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Henderson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Valerian Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Valerian needs ~2,512 GDD — county provides 3,500 GDD Excellent fit

Valerian Planting Timeline — Henderson County, KY

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors April 12 Apr 12 – Apr 26
Harvest August 16 Aug 16 – Oct 25

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May
June
July
August Harvest
September Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

209 days in Henderson County

Growing Tips for Valerian in Henderson County

Direct sow Valerian outdoors after April 05 in Henderson County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors and transplant after last frost. Harvest roots in fall of the second year. Deadhead flowers unless you want self-seeding. Cats are attracted to valerian root.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Valerian in Henderson County, KY?

Henderson County is in Zone 6b with an average last frost of April 5. Plan your Valerian planting based on this frost date — see the calendar above for exact timing.

What planting zone is Henderson County, KY?

Henderson County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 5 and first fall frost is October 31.

🌱

Your Henderson County Garden Planner — Free

A 24-page printable planner built for Henderson County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Henderson County, KY. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.